This invention relates to a quick connect coupling for transmitting gaseous and/or liquid fluids, especially for filling gas tanks.
A reliable, tight and rapidly connected plug-in coupling has to be provided by such quick connect couplings, for transmitting a fluid from a pressure source, for example a refilling cylinder or a pressure tank. Simple, problem-free operation of the quick connect coupling is particularly important, so that problem-free handling is made possible, even under unfavourable conditions, such as with dangerous fluids or high connection pressures.
Such a quick connect coupling is described in EP-A 0 340 879, wherein the quick connect coupling comprises a housing with a fluid inlet and a fluid outlet, as well as a plurality of valves, in order to ensure reliable sealing of the quick connect coupling until the connection is completely effected. These valves are operated after attaching the quick connect coupling in a specific, predetermined sequence, wherein the outlet valve is opened first, then the collet jaws are closed by further movement of a control lever and finally the inlet valve is opened. The control lever engages via an eccentric shaft with the sliding sleeve for actuating the collet jaws and with a central sealed piston, which also opens the fluid inlet after completed attachment of the plug-in coupling.
Although a particularly secure connection is provided by this, the structure of this coupling is relatively expensive, on account of the many components. In addition, operation is relatively complex, since the operation of the control lever is necessary in addition to plugging in the coupling, so that single-handed operation is hardly possible.
Such a quick connector is further known from WO-A 93/20378 of the applicant, especially for filling gas cylinders, wherein a quick connect device in the form of collet jaws with an engagement profile is provided in the region of the outlet. A hollow sealing piston slidably movable in the coupling housing is also described, being connected trough an actuating device connected to a sliding sleeve for closing and opening the collet jaws. The handling of his quick connect coupling is also open to improvement. Further plug-in couplings are known from EP 0 382 723 and DE 3 518 019 of the applicant, in which similar disadvantages apply, in particular canted attachment of the connection coupling and thus its opening with fluid release with (still) incompletely made sealing connection cannot be completely ruled out.
Accordingly the invention is based on the object of providing a quick connect coupling of the kind initially specified which facilitates particularly reliable and simple handling with a simple structure,
This object is met by a quick connect coupling for transmitting gaseous and/or liquid fluids. The quick connect coupling includes a tubular housing, spreadable locking elements fixed on the housing for connection to a correspondingly formed connector, and a sealing piston slidable centrally in the housing for engagement with the connector. The sealing piston is surrounded by an axially movable sliding sleeve which retains the locking elements in the locking position in the coupled position of the quick connect coupling. Preferred developments of the invention form the subject matter of the dependent claims.
The proposed quick connect coupling is distinguished by simple operation, which is also particularly reliable, since it can be coupled up and uncoupled with hardly any force. This proposed quick connect coupling is suitable for different connectors, especially for connecting nipples of gas tanks and for gas cylinder valves. Through the sealing piston which can slide or telescope in the housing, a more secure engagement of the locking elements, especially of the collet jaws, since the engagement profile of the collet jaws automatically adapts to the corresponding interlocking engagement profile of the complementary connector by virtue of the ability of the sealing piston to slide and the locking elements, especially the collet jaws are locked independently of the sealing piston. This is especially important, since the corresponding connection nipple, e.g. for a gas tank, can be made relatively simple. Because of the ability of the sealing piston to slide axially, a reliable, tight engagement between the engagement profile and the sealing surface at the end surface of the quick connect coupling results and only then does the outlet or check valve coupled thereto open. In particular excessively canted application of the coupling is avoided by this, i.e. the user is constrained to correct fitting, since both the opening of the fluid passage and also the coupling up at the coupling side are otherwise prevented. Wear of or damage to the connecting profile is also reliably avoided through this, on both the coupling and the nipple side.
The realisation of the quick connect coupling by means of an outer control sleeve is also especially important, preferably for pneumatic actuation of the coupling, so that a reliable and rapid, one-handed operation of the quick connect coupling is facilitated in an especially simple manner.